Hot gas rotary piston engine

ABSTRACT

A hot gas engine in the form of a rotary piston engine of trochoidal construction in which two rotary piston engines operate with predetermined phase displacement, of which one is constructed as hot gas section and the other one as cold gas section; each rotary piston engine includes a triangular piston rotatably supported on an eccentric shaft within an epitrochoidally shaped two-arched housing case whereby inlet and outlet openings are provided in the contact surface of the casing in front and to the rear of the minor axis; the inlet and outlet openings are arranged both in the hot gas section as also in the cold gas section mutually opposite one another and are connected with each other by way of branch lines provided with control devices and main lines that include heaters, regenerators and coolers interconnected in the main lines.

United States Patent [191 Wahnschaffe et a1.

[ HOT GAS ROTARY PISTON ENGINE [75 Inventors: J urgen Wahnschaffe, Cologne; Dietrich Gwinner, Waiblingen; Konstantin Pattas, Stuttgart; Eberhard Braun, Waiblingen, all of Germany [73] Assignee: Daimler-Benz Aktiengesellschaft,

Stuttgart, Germany [22] Filed: Mar. 29, 1971 [21] Appl. No.: 128,665

[30] Foreign Application Priority Data 57 ABSTRACT A hot gas engine in the form of a rotary piston engine of trochoidal construction in which two rotary piston engines operate with predetermined phase displacement, of which one is constructed as hot gas section and the other one as cold gas section; each rotary piston engine includes a triangular piston rotatably supported on an eccentric shaft within an epitrochoidally shaped two-arched housing case whereby inlet and outlet openings are provided in the contact surface of the casing in front and to the rear of the minor axis; the inlet and outlet openings are arranged both in the hot gas section as also in the cold gas section mutually opposite one another and are connected with each other by way of branch lines provided with control devices and main lines that include heaters, regenerators and coolers interconnected in the main lines.

12 Claims, 1 Drawing Figure PATENTED 9|975 3.763.649

INVENTORS JURGEN WAHN'SCHAFFE DIETRICH GWINNER KONSTANTIN PATTAS EBERHARD BRAUN %n:w;,sw yum,

ATTORNEYS HOT GAS ROTARY PISTON ENGINE The present invention relates to a hot gas engine in the form of a rotary piston engine of trochoidal type of construction.

The present invention is concerned with the task to utilize rotary piston engines in an advantageous manner compared to the hitherto customary double-acting Stirling reciprocating piston engines operating with discontinuous movements according to the hot gas principle.

The solution according to the present invention utilizes two rotary piston engines operating with phase displacement of which one is constructed as hot gas portion and the other as cold gas portion, each including a triangular piston as inner envelope rotatably supported in a conventional manner on an eccentric shaft and an epitrochoidally shaped, two-arched casing housing, and which are provided at the casing running surfaces thereof with inlet and outlet openings each on both sides, respectively, in front and behind (upstream and downstream) of the minor axes as viewed in the direction of rotation of the piston, of which the respective inlet and outlet openings are arranged both in the hot gas as also in the cold gas portion mutually diagonally opposite and are connected with each other by way of branch lines provided with control devices and main lines under interposition of a heater, a regenerator and a cooler each.

in a preferred embodiment, the present invention proposes to construct thecontrol devices arranged between the main line and the lines branching off from the same as roller-type slide valves.

The hot gas process with multi-fuel capability and noise-free operation realized in this manner by means of two rotary piston engines offers the advantage of a complete mass compensation and a small specific weight by reason of the compact structure.

Additionally, a facilitated control of the heat stresses occurring in the housing of the rotary piston engines is realized by reason of the mutually separated warm and cold spaces.

Accordingly, it is an object of the present invention to provide a hot gas rotary piston engine which avoids the aforementioned shortcomings and drawbacks encountered in the prior art.

Another object of the present invention resides in a hot gas rotary piston engine which obviates the discontinuous movements of the prior art engines operating according to the hot gas principle.

A further object of the present invention resides in .a hot gas engine which not only reduces the problems of thermal'stresses but also enables a smaller weight per horsepower as well as complete mass compensation.

These and further objects, features and advantages of the present invention will become more obvious from the following description when taken in connection with the'accompanying drawing which shows, for purposes of illustration only, one embodiment in accordance with the present invention, and wherein:

The single FIGURE is a schematic view of one embodiment of a hot gas rotary piston engine in accordance with the present invention.

Referring now to the single FIGURE of the drawing, the embodiment shown therein illustrates two rotary piston engines operable for hot gas operation, of which the rotary piston engine constructed as hot gas section is generally designated by reference numeral 1a, and

the rotary piston engine operating as cold gas section is generally designated by reference numeral 1b.

The rotary piston engine 1a consists of a stationary, epitrochoidally shaped two-arched casing housing 2 and of a triangular piston 4 provided with three sealing bars 3, which is rotatably supported on an eccentric of an eccentric shaft (not shown) and rotates in the same direction as the eccentric shaft which in a conventional manner for such engines carries out three rotations during each rotation of the piston. Since the details of such rotary piston engines are known as such, a detailed showing and description thereof is dispensed with herein. The casing housing 2 provided with a casing running or contact surface 5 is provided on each side of the minor axis 6 with two mutually diagonally opposite inlet openings 70, 7b and outlet openings 8a, 8b, whereby the inlet openings and 7b are arranged shortly behind (downstream of) the minor axis 6 as viewed in the direction of rotation of the piston 4, indicated by the arrow, and the outlet openings 8a, 8b are disposed shortly in front (upstream) of the minor axis 6.

The openings arranged pair-wise on both sides of the casing housing 2 of the rotary piston engine la constructed as hot gas section are connected with the openings arranged pair-wise in an analogous manner in the cold gas section of the rotary piston engine lb, which are designated as inlet openings by reference numerals 9a, 9b and outlet openings by reference numerals 10a, 10b, by way of branch lines and 13b, 14a and 14b, 15a and 15b and 16a and 16b terminating in the main lines 1 l and 12. The ends of the main lines 11, 12 are provided each with a control device 17 constructed as rotary slide valve which controls the gas flow, flowing with a periodical change of the flow direction, through the lines branching off from the main lines ll, 12. Both main lines ll, 12 are provided, respectively, with a heater 18a, 18b, a regenerator 19a, 19b and a cooler 20a, 20b, all of any conventional construction.

The pistons 4 of the rotary piston engines la and lb are arranged displaced with respect to each other by 90 whereby the hot gas piston leads the cold gas piston by 270 eccentric shaft angle. The rotary slide valves 17 for the control of the gas flow rotate at the eccentric shaft rotational speed so that during one eccentric shaft rotation the chambers designated by reference numeral 21 or the chambers designated by reference numeral 22 are alternately connected with the line system during 180 eccentric shaft angle.

The rotary piston engines provided with circumferential control in the surfaces 5, as shown in the drawing, may be replaced for reasons of a considerably more compact construction possibly by rotary piston internal combustion engines, whose inlet and outlet openings are not arranged in the running surfaces 5 of the casings but at the lateral wall parts (not shown) of the engme.

While we have shown and described only one embodiment in accordance with the present invention, it is understood that the same is not limited thereto but is susceptible of numerous changes and modifications as known to those skilled in the art, and we therefore do not wish to be limited to the details shown and described herein, but intend to cover all such changes and modifications as are encompassed by the scope of the appended claims.

We claim:

1. A hot gas engine comprising first and second troichoidal chambers, said first chamber being constructed as a hot gas section and said second chamber being constructedas a cold gas section, a polygonal piston rotatably mounted in each chamber, two inlet ports and two outlet ports in each of said chambers, said inlet ports being arranged diagonally opposite one another at first and second sides of each of said chambers, said outlet ports being arranged diagonally opposite one another at said first and second sides of each of said chambers, a first branch line means communicating directly with the inlet port at the first side of the first chamber, a second branch line means communicating directly with the outlet port at the first side of the first chamber, a third branch line means communicating directly with the inlet port at the first side of the second chamber, a fourth branch line means communicating directly with the outlet port at the first side of the second chamber, first main line means, first control valve means for selectively communicating one of the first and second branch line means with one end of said first main lines means, and second control valve means for selectively communicating one of the third and fourth branch line means with the opposite end of said first main line means.

2. A hot gas engine according to claim 1, further comprising a fifth branch line means communicating directly with the inlet port at the second side of the first chamber, a sixth branch line means communicating directly with the outlet port at the second side of the first chamber, a seventh branch line means communicating directly with the inlet port at the second side of the second chamber, an eigth branch line means communicating directly with the outlet port at the second side of 4. A hot gas engine according to claim 3, further comprising regenerator means and cooler means in each of said first and second main line means, wherein said heater means, regenerator means and cooler means are arranged in series relationship to one another in the main line means.

5. A hot gas engine according to claim 1, wherein the position of said first and second control valve means is dependent on the instantaneous position of the engine pistons. I

6. A hot gas engine according to claim 1, wherein said first and second control valve means are constructed as rotary slide valves.

7. A hot gas engine according to claim 6, wherein saidrotary slide valves are interconnected to the engine pistons so as to rotate at a predetermined rate with respect to the rotational rate of the pistons.

8. A hot gas engine according to claim 2, wherein each of said first, second, third and fourth control valve means are constructed as rotary slide valves.

9. A hot gas engine according to claim 8, wherein said rotary slide valves are interconnected to the engine pistons so as to rotate at a predetermined rate with respect to the rotational rate of the pistons.

10. A hot gas engine according to claim 1, wherein communication of respective first and second branch line means with respective third and fourth branch line means is only by way of said first main line means.

11. A hot gas engine according to claim 2, wherein communication of respective branch line means at one chamber with respective branch line means at the other chamber is only by way of said first and second main line means such that flow takes place in one direction in the respective main line means during part of the engine: operating cycle and in the opposite direction during another part of the engine operating cycle.

12 A hot gas engine according to claim 4, wherein communication of respective branch line means at one chamber with respective branch line means at the other chamber is only by way of said first and second main line !means such that flow takes place in one direction in tlie respective main line means during part of the enginei operating cycle and in the opposite direction during another part of the engine operating cycle. 

1. A hot gas engine comprising first and second troichoidal chambers, said first chamber being constructed as a hot gas section and said second chamber being constructed as a cold gas section, a polygonal piston rotatably mounted in each chamber, two inlet ports and two outlet ports in each of said chambers, said inlet ports being arranged diagonally opposite one another at first and second sides of each of said chambers, said outlet ports being arranged diagonally opposite one another at said first and second sides of each of said chambers, a first branch line means communicating directly with the inlet port at the first side of the first chamber, a second branch line means communicating directly with the outlet port at the first side of the first chamber, a third branch line means communicating directly with the inlet port at the first side of the second chamber, a fourth branch line means communicating directly with the outlet port at the first side of the second chamber, first main line means, first control valve means for selectively communicating one of the first and second branch line means with one end of said first main lines means, and second control valve means for selectively communicating one of the third and fourth branch line means with the opposite end of said first main line means.
 2. A hot gas engine according to claim 1, further comprising a fifth branch line means communicating directly with the inlet port at the second side of the first chamber, a sixth branch line means communicating directly with the outlet port at the second side of the first chamber, a seventh branch line means communicating directly with the inlet port at the second side of the second chamber, an eigth branch line means communicating directly with the outlet port at the second side of the second chamber, second main line means, third control valve means for selectively communicating one of the fifth and sixth branch line means with one end of said second main line means, and fourth control valve means for selectively communicating one of the seventh and eigth branch line means with the opposite end of said second main line means.
 3. A hot gas engine according to claim 2, further comprising heating means arranged in each of said first and second main line means.
 4. A hot gas engine according to claim 3, further comprising regenerator means and cooler means in each of said first and second main line means, wherein said heater means, regenerator means and cooler means are arranged in series relationship to one another in the main line means.
 5. A hot gas engine according to claim 1, wherein the position of said first and second control valve means is dependent on the instantaneous position of the engine pistons.
 6. A hot gas engine according to claim 1, wherein said first and second control valve means are constructed as rotary slide valves.
 7. A hot gas engine according to claim 6, wherein said rotary slide valves are interconnected to the engine pistons so as to rotate at a predetermined rate with respect to the rotational rate of the pistons.
 8. A hot gas engine according to claim 2, wherein each of said first, second, third and fourth control valve means are constructed as rotary slide valves.
 9. A hot gas engine according to claim 8, wherein said rotary slide valves are interconnected to the engine pistons so as to rotate at a predetermined rate with respect to the rotational rate of the pistons.
 10. A hot gas engine according to claim 1, wherein communication of respective first and second branch line means with respective Third and fourth branch line means is only by way of said first main line means.
 11. A hot gas engine according to claim 2, wherein communication of respective branch line means at one chamber with respective branch line means at the other chamber is only by way of said first and second main line means such that flow takes place in one direction in the respective main line means during part of the engine operating cycle and in the opposite direction during another part of the engine operating cycle.
 12. A hot gas engine according to claim 4, wherein communication of respective branch line means at one chamber with respective branch line means at the other chamber is only by way of said first and second main line means such that flow takes place in one direction in the respective main line means during part of the engine operating cycle and in the opposite direction during another part of the engine operating cycle. 